In mid-December last year, following a humiliating cup defeat, an enraged Inter fan threw a Molotov cocktail outside the San Siro stadium. This was significant for two reasons. First because it suggested a disturbing level of preparation. And second because of the incendiary's intended victims. It hit and damaged the coach carrying the Inter team, in other words the highly priced players the Inter fans cheer every week. Marco Tardelli, the coach, was one of many on board badly shaken by the attack. 'I just cannot accept this type of violence bursting its way into football,' he said. 'After the Heysel disaster, this is the worst that's ever happened to me in football. Next thing they'll be shooting at us from the grandstand.'

The firebomb was just one example of an escalating crisis, with a huge increase in the number of violent incidents(see panel). One disturbing trend has been the proliferation of attacks by supporters on their own team or team officials, whether it be Roma fans ambushing players arriving at the Trigoria training ground, Brescia supporters smashing the window of a car carrying their club president's daughter, Pescara forced to train under police protection, Reggina president Pasquale Foti receiving a severed calf's head in the post, or Napoli ultras lobbing a bomb into the garden of the club's part-owner Corrado Ferlaino.

Not that the violence has been limited to fans turning on their own. In some towns and cities it has become almost routine with railway and bus stations hosting battles between rival supporters. Three Serie A clubs - Napoli, Reggina and Vicenza Ü have been ordered to play home games away from their own stadium this season as a punishment for their fans' violent behaviour.

To an extent the increasing violence can be traced to the same dynamic as the increased racism: orchestration by politically motivated infiltrators. But there are other causes. Some are banal: an early season clash between rivals almost guarantees a revenge cycle. The police, too, are often the intended victims; indeed, for many ultras the police Ü as the embodiment of authority - are the primary target. 'They want to stop me doing what I want to do,' Lorenzo, the head of the Roma ultras told Channel Four. 'So I must react violently. That's what the young guys in the curva think. The Curva is a territory that the ultras must defend.'

Sometimes opposition fans are deliberately attacked to provoke the police. Friends of a badly beaten Roma fan vowed revenge at the next match - which happened to be against Liverpool. According to one ultra, Liverpool supporters were stabbed solely to draw in police. It worked. Bottles, stones and petrol bombs rained down as soon as they arrived.

Giuliano Zincone, the Corriere della Sera columnist, provides an almost Hobbesian analysis of the racism and violence, with football providing a safety valve for a society of base, violent instincts.

'The sports stadium is the only, and perhaps the last remaining place where extreme, cruel, dirty and primitive feelings are expressed,' he writes. 'It is the open-air catacomb for the barbaric custom of wishing the greatest possible misfortune on one's rivals, cast as infidels. That's the way it is. There is, and long has been, a minority that likes to go to the stadium in order to shout disgusting slogans, to vent hostility and give voice to the aggression and antagonism that are prohibited elsewhere.

'Many people go to the stadium for the specific purpose of "offending". Unleashing the spirit of rebellion and complete antagonism is part of the modern soccer stadium just as cruelty was part of the operational functions of the Roman Colosseum. In the stadium, verbal violence can serve as a proxy for real violence.

'The stadium is the platform for an almost religious and warlike devotion to one's favourite team... the vile banners do not, as a rule, express actual political inclinations, but reflect a vague desire to "be somewhere else", to seek direct conflicts rather than languish constantly in the bland repression and pacifications required by everyday collective life.

'Cruel sentiments exist and perhaps it is better to contain them, to let them shout themselves out in stadiums, than to prohibit them there and find them cropping up again, ominously, in city streets and squares.'

'Only suckers stick to the rules if the game is rigged,' writes a Juventus fan on an ultra website. It is a refrain heard all over Italy. Rumours of Serie A corruption surface weekly, fuelling a sense that the league operates above the law.

The revelation that Lazio's Argentine star midfielder Juan Veron had a forged Italian passport shocked the league. Dozens of clubs and foreign players are under investigation for allegedly faking documents and inventing Italian ancestors to circumvent limits on non-European Union players. Prodded into action by Fifa, the Italian federation has yet to reach conclusions but stars such as Inter's Uruguayan forward Alvaro Recoba are unlikely to emerge unscathed. Time will tell whether the villains were players, agents or clubs. All protest their innocence.

Italy is not the only country tarnished by the passports scandal Ü but only Italy could come up with the Night of the Watches. Gold Rolexes given by Roma to referees were returned lest the 'Christmas presents' conveyed the wrong impression. A federation inquiry flushed out expensive offerings from other clubs, such as holidays paid by Juventus. 'Where does the fine line between a kind gift and a bribe lie?' asked Corriere della Sera. The perception that Serie A's referees are on the take is widespread, the image of it as a corrupt league, long lasting and difficult to shift.

A year ago as the Serie A title built toa nail-bitingly close climax, Juventus benefited from an extraordinary piece of refereeing against Parma. A last-minute equaliser was inexplicably disallowed, giving Juve a dubious and vital victory with one week of the season left. A tidal wave of anti-Juve feeling swept Italy including a street 'funeral for Italian football' and the front page headline on the Corriere dello Sport, 'Sorry, but this is a scandal'. (Juventus lost their final game and the championship went to Lazio after all.) This was in the same season that an Italian Serie A player wrote a letter to the Catholic magazine Famiglia Cristiana claiming he was bribed to lose a match. The magazine rebuffed magistrates' inquiries, saying its letters column was akin to a confessional.

Juve have been accused before. Three years ago the 'season of poison' culminated in a controversial game in which Inter were denied a blatant penalty. 'Referees don't do this on purpose,' raged the Inter president Massimo Moratti, 'it's a habit. They are afraid of hurting Juventus. It is the rule, not the exception.' The former Italian international Roberto Mancini went a lot further, saying 'the last fair championship was won in 1991 by Sampdoria'.

This season has seen new match-fixing scandals. A cup match between Atlanta and Pistoiese provoked much interest after a rush of inspired bets that the game would end 1-1, with a goal in each half - bets that proved extremely prescient. After a long investigation the allegations of match-fixing were upheld against six players who were banned for up to a year. Also this season, Perugia's coach Serge Cosmi while talking in a TV studio before an interview, alleged that the Italian Third Division (in which he was a coach last season) was a giant fix. His remarks were filmed and were later shown. They are now the subject of another investigation.

This season has seen another growing area of potential corruption Ü footballers failing drugs tests. A fortnight ago Edgar Davids became the latest, and the highest profile player to join the list. The Dutch international and mainstay of the Juventus midfield tested positive for the steroid nandrolone after a sample was taken following a game in early March. Davids insists he is innocent and the authorities are awaiting the result of a second test before deciding on what action to take.

Already this season four Serie A players (and one from Serie B) have been confirmed as failing tests, including Lazio's Portuguese international defender Fernando Couto, who was suspended 10 days ago, prior to being sentenced by the Italian Olympic Committee on Tuesday. Two players are already serving 16-month bans. There has been much talk among players about dietary supplements and better supervision of the use of prescription medicines, but a more sinister assessment of football's drugs culture came from former Parma coach Nevio Scala. 'It's a nonsense to say nobody is guilty,' he said. 'At the crucial time of the season, when results are decisive and players tired, there are people who are prepared to act incorrectly and administer forbidden substances.'

A couple of years ago the former Roma and Napoli coach Zdenek Zeman caused outrage with his claim that doping was rife in Italian football. In total, eight players have now failed drugs tests since random screening was introduced, while a further 67 are under investigation by the Turin public prosecutor's office. The response of Italian clubs? To try to raise the level of nandrolone allowed in a player's bloodstream before a test is deemed positive - a move rejected by the Italian football association who insisted on adhering to the limits recommended by Fifa.

Once again calcio is left looking sleazy. The same could be said for the country. Transparency International, a non-governmental agency, ranks Italy's corruption on a par with the Third World. Silvio Berlusconi, the billionaire opposition leader and likely Prime Minister, is sought by a Spanish court on suspicion of bribery. Football's failure to buck the trend diffuses moral pollution through Serie A. If clubs flout the rules why shouldn't fans? It is a sentiment that threads racism, violence and corruption into a vicious circle.

Churning beneath the surface of Italian football's problems is a deeper explanation. Alienation. According to the ultras, greed has swept away a golden age when officials, players and fans were united in love of their club, a bond that would last even in dark years of relegation. Satellite television's lucre has turned officials into entrepreneurs and players into mercenaries. Only the fans have stayed true.

So goes the mythology. The ultras see clubs enriching players and officials while hiking ticket prices. They see clubs negotiating huge sponsorship deals and refusing to subsidise away travel. They see clubs selling iconic players despite furious protests. They see betrayal. Throughout Serie A the theme recurs. Fans are the keepers of the flame, defenders of the faith. It is their duty to safeguard the club's integrity, with violence if necessary.

The next few weeks will decide who wins the title. Roma have led for most of the season: can they hold their nerve in the face of Juve's impressive late surge? But in many ways it doesn't matter who wins. No amount of passion and skill can cover the fact that this season everybody has lost.

Back on the Curva Nord, Marco expresses the view of many. 'The league stinks,' he says bitterly. 'You can smell the rot.'

Italian football violence: a season of savagery

October 2000

Piacenza v Atalanta A riot breaks out at Piacenza train station. Objects are thrown out of the train window, including a bicycle. Ten policemen are injured.

Napoli v Bologna Napoli fans inside the stadium throw objects at the police, who try to calm things using tear gas, which drifts onto the pitch, halting the match. The riot continues outside the stadium. Two policemen are injured and a fan is hit by a homemade bomb.

Milan v Juventus A Milan fan throws a flare into the Juve section during the match. Police intervene as Juve fans become aggressive. Milan fans throw flares, fruit and bottles throughout the match.

November

Reggina v Brescia Reggina fans force the game to be abandoned by throwing objects onto the field. These fans, including the son of San Angelo de Lombardi's archbishop, have been banned for a year.

Como v Modena In a post-match brawl Como's Massimo Ferrigno knocks Modena midfielder Francesco Bertolotti to the ground, putting him in a coma that lasts eight days. Ferrigno has been banned until the end of 2003. Bertolotti still requires a number of operations.

December

Fan attacks owner A Napoli fan throws a bomb into the garden of the club's co-owner Corrado Ferlaino in reaction to the club's poor start to the season.

Inter v Parma Inter's team bus is attacked by a fan, who throws a petrol-bomb at players sat aboard the bus. The device bounces off the window and explodes in the street.

Inter v Juventus Juventus fans throw chairs and rocks at the police after the match, a 2-2 draw. Police are forced to use tear gas until back-up arrives to help restore order.

Milan v Roma Police fight with Roma fans for 15 minutes after the match. Fans throw flares and rip out seats. The police respond by using batons to drive back the supporters and finally restore order with heavy use of tear gas.

February 2001

Pisa v La Spezia La Spezia fans set fire to seats inside Pisa's ground and throw them onto the pitch. One of them hits the Pisa goalkeeper. Police fight with travelling fans throughout the game. Twelve people are injured.

Atalanta v Vicenza Two policemen are injured by a firecracker thrown by a Vicenza fan. One policeman, who tried to catch the firecracker in an attempt to protect supporters from injury, badly burns his hand and has to have a finger amputated.

Foggia v Tricase The game is suspended after 87 minutes when a firecracker is thrown onto the pitch. Cars are damaged by Foggia supporters, who had earlier tried to invade the dressing rooms.